The impact of free vaccination policies under the Korean Influenza National Immunization Program: Trends in influenza vaccination rates in South Korea from 2010 to 2019

Abstract

Background Annual vaccination for influenza is recommended for high-risk populations for its high morbidity and mortality. South Korea provides free influenza vaccination to some target groups under the National Immunization Program (NIP), and discrepantly high vaccination rates are observed in such populations. In this study, we analyzed the trends in influenza vaccination rates and evaluated the impact of the recent expansion of financial coverage to children ≤12 years and pregnant women. Methods We conducted a cross-sectional study with nationwide survey data from Korea National Health and Nutrition Examination Survey (KNHANES). From 2010 to 2019, we evaluated the trends in influenza vaccination rates of the following four target groups: children ≤12 years, adults ≥65 years, pregnant women, and people with chronic diseases. Results In total, 80,861 individuals were analyzed. From 2017 to 2019, the vaccination coverage of children ≤12 years increased from 66.2% to 83.1%; pregnant women from 44.1% to 68.5% (comparing the mean of 2010–2017 and 2018–2019, P <0.001 for both). The elderly ≥65 years showed the highest rates (85.8% in 2019), while people with chronic diseases marked the lowest (41.9% in 2019). People with liver diseases showed the lowest vaccination rate of 27.8%, while that of other common diseases ranged between 31.7–44.1%. Conclusion The discrepancy between target groups corresponds to their financial coverage under NIP. The recent expansion of financial aids to children ≤12 years and pregnant women was followed by significant increases in vaccination rates in both groups. We suggest that free vaccination policy is one of the most effective strategies to enhance vaccination coverage, and we call for its expansion to other under-vaccinated target groups, especially people with chronic diseases.

Influenza vaccination trend and related factors among patients with diabetes in Korea: Analysis using a nationwide database

“…Previous studies have consistently demonstrated similar results (34-36). The results from a recent study conducted in Korea also showed that a lower education level was associated with higher influenza vaccination coverage (37). It might be that people with low education levels have the need for preventive management because they have more possibility to work in fields that require more physical activities and less social support.…”

The impact of the COVID-19 pandemic and the expansion of free vaccination policy on influenza vaccination coverage: An analysis of vaccination behavior in South Korea

“…Discrepancy in vaccination coverages among target groups was also present: relatively low coverages were observed in pregnant women and people with chronic diseases. Previous studies showed that financial support is one of the most powerful factors which enhance influenza vaccination coverages [ 6 , 12 , 20 , 21 ]. As shown in Fig 1 , vaccination coverages of children ≤12 increased steeply after 2017–2018 along with the start of free vaccination.…”

“…Four subgroups were selected as target groups in our previous studies: adults aged ≥65, children aged ≤12, pregnant women, and people aged 19–64 with chronic diseases [ 6 , 12 ]. In the present study, considering the policy changes in 2020, we added two target subgroups: adults aged 62–64 and children aged 13–18.…”

Cost-Effectiveness of Extending the National Influenza Vaccination Program in South Korea: Does Vaccination of Older Adults Provide Health Benefits to the Entire Population?

“…For example, vaccination for children under 12 years old was gradually extended from 2016 to 2018, and the coverage rate increased dramatically from 61.2% in 2014 to 83.1% in 2019. In addition, when free vaccination was made available to pregnant women in 2019, the vaccination rate increased from 36.5% in 2014 to 68.5% in 2019 [57]. The effect of the free vaccination policy is not limited to South Korea.…”